Westfalia James Cook and Airstream Westfalia

Replacing the water heater anode rod

I’m gradually catching up with all of the required maintenance, and this weekend tackled the anode rod in the water heater. I’d been meaning to do it for a while – I’d never replaced it myself, and had no idea when it was last replaced by the previous owner.

To get the old rod out, you’ll need a 1 1/16″ socket (a wrench won’t fit). I didn’t have that socket but did have a 27mm socket that fit perfectly.

After a few turns of the bolt head, the water in the tank came shooting out in a great burst! I found myself covered with water as well as what I presume to be calcium deposits 🙂 The rest of the water proceeded to drain out of the tank through the anode rod’s hole – perhaps it also drained my fresh water tank at the same time? Once all the water was out I directed a garden hose into the hole to try and flush out all of the gunk I could feel at the bottom of the tank. There was a lot!

A hint for anyone else doing this: park very close to a drain when you do this. The amount of calcium deposits in the tank is amazing!! After hosing it all off of my driveway I’m left with a broad white strip at the bottom of the drive.

The new rod just screws right in. It’s an easy, 5-10 minute job; 2 minutes if you don’t need to rinse your tank.

2 Responses to Replacing the water heater anode rod

I believe the socket size is actually 1 1/8 inches. I used a 1/4 inch copper tube connected to hose and inserted it into the anode hole to flush out the deposits, bending it as needed to reach everywhere. I believe the deposits are magnesium hydroxide and the pressure that develops in the tank when sitting may be H2 gas. 2 H20 + Mg -> Mg(OH)2 + H2
The very pure mountain water you get from campgrounds is very soft and corrosive compared to well water or city water where they may add anti corrosives to reduce lead leaching from solder. Tastes better, but the purer the water, the more it wants to dissolve stuff.

Thanks Rob! Good info. I was wrong with 1 1/4″ – you were closer, but the actual size is 1 1/16″! Interesting note about campground water. I have to admit that I never drink from the Westy’s fresh water system, but instead bring a jug of water. I’d like to buy a filter jug instead.